设ATM网复用器的信元输入率依赖于一个交替更新过程（而非马尔可夫过程），复用器的输出率恒定不变，缓冲器的信元初始容量为0。在此条件下，应用流体模型和更新理论，求出了在任意时刻t时缓冲器容量Q（t）的概率分布，为缓冲器的设计和控制提供了有力的理论依据。 Let ATM cell multiplexer cell input rate depends on an alternating update process (rather than Markov process), the output rate of the multiplexer is constant, the initial cell buffer capacity of 0. Under these conditions, the probability distribution of the buffer capacity Q (t) at any time t is obtained by applying the fluid model and the renewal theory, which provides a powerful theoretical basis for the design and control of the buffer.